Mid-Depth Soil Collected for Lab Test On NASA's Mars Lander

Aug 22, 2008

Soil from a sample called Burning Coals was delivered through the doors of cell number seven (left) of the Thermal and Evolved-Gas Analyzer. Image credit: NASA/JPL-Caltech/University of Arizona/Max Planck Institute

NASA's Phoenix Mars Lander has scooped up a soil sample from an intermediate depth between the ground surface and a subsurface icy layer. The sample was delivered to a laboratory oven on the spacecraft.

The robotic arm on Phoenix collected the sample, dubbed "Burning Coals," from a trench named "Burn Alive 3." The sample consisted of about one-fourth to one-half teaspoon of loose soil scooped from depth about 3 centimeters (1.2 inch) below the surface of the ground and about 1 centimeter (0.4 inch) above a hard, icy underground layer.

Data received from Phoenix early Thursday confirmed that the arm had delivered some of that sample through the doors of cell 7 on the lander's Thermal and Evolved Gas Analyzer (TEGA) and that enough material passed through a screen and down a funnel to nearly fill the cell's tiny oven. The Phoenix team prepared commands Thursday to have TEGA close the oven and begin heating the sample to low temperature (35 degrees Celsius, or 95 degrees Fahrenheit).

The purpose of the low temperature heating is to look for ice in the sample. The next step is a middle temperature process, which heats the sample to 125 degrees Celsius (257 degrees Fahrenheit) to thoroughly dry the sample. The last heating takes the sample to 1000 degrees Celsius (1832 degrees Fahrenheit). The gases given off during these heating stages help the science team to determine properties of the Martian soil.

"We are expecting the sample to look similar to previous samples," said William Boynton of the University of Arizona, lead scientist for TEGA. "One of the things we'll be looking for is an oxygen release indicative of perchlorate."

Perchlorate was found in a sample delivered to Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The MECA team saw the perchlorate signal in a sample taken from a trench called "Dodo-Goldilocks" on June 25, and again in another sample taken from the "Rosy Red" trench on July 6. To see signs of perchlorate in TEGA would help confirm the previous results. Scientists are analyzing data from a Rosy Red surface sample heated in TEGA cell number 5 last week.

The new sample in cell 7 completes a three-level soil profile that also includes the surface material (from Rosy Red) and ice-layer material (from a trench called "Snow White").

"We want to know the structure and composition of the soil at the surface, at the ice and in-between to help answer questions about the movement of water -- either as vapor or liquid -- between the icy layer and the surface," said Ray Arvidson of Washington University in St. Louis, a leader of Phoenix science team activities.

A new technique invented at Caltech to produce graphene—a material made up of an atom-thick layer of carbon—at room temperature could help pave the way for commercially feasible graphene-based solar cells ...

NASA's Cassini spacecraft has measured a curious abundance of methane spewing into the atmosphere of Saturn's icy moon Enceladus. A team of American and French scientists published findings in Geophysical Re ...

Physicists from Forschungszentrum Jülich have developed a criterion with which scientists can seek suitable substrate materials for graphene in a targeted way. Interactions with the substrate material often ...

At least two thousand years before the ancient Egyptians began mummifying their pharaohs, a hunter-gatherer people called the Chinchorro living along the coast of modern-day Chile and Peru developed elaborate ...

When the research vessel JOIDES Resolution returned to port in late January after a two-month cruise, it had harvested more than 550 sediment cores from deep beneath the Indian Ocean. Locked within those ...

A team of scientists has a new explanation for the planet Mercury's dark, barely reflective surface. In a paper published in Nature Geoscience, the researchers suggest that a steady dusting of carbon from p ...

You can be thankful that we bask in the glow of a relatively placid star. Currently about halfway along its 10 billion year career on the Main Sequence, our sun fuses hydrogen into helium in a battle against ...

User comments : 0

Please sign in to add a comment.
Registration is free, and takes less than a minute.
Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.